I'm setting up an Raspberry Pi 3 as a new frontend using Raspbian stretch and MythTV Light (excellent work, thanks for those packages!). I bought an MPG2 license key (source is UK Freesat) and playback is fine for SD shows. There are some hints in other threads about options that might improve playback and have HD working too, so I'm going to try those before asking for help there.

However, the OSD won't display. I've fiddled with some of the settings for this but it just won't display. I'm using the OpenMAX High Quality playback profile and it looks from the wiki like I should be using the opengl OSD renderer. It did show up using softblend but that made the video jerky. Does anyone have any ideas on how to get the OSD to display?

I have GPU memory set to 320, and am running MythTV 29. The audio change I will try tonight, as posted by you on another thread:

pgbennett wrote: For audio over HDMI, either of the following will work
1. Use raspi-config to force audio over HDMI and in MythTV frontend audio setup select ALSA default.
2. In front end audio setup select OpenMAX HDMI, uncheck the digital options (Dolby etc.), make sure to select Stereo for speakers, and in the next page select Openmax for mixer. When starting playback press volume up (right square bracket]) until the volume goes up enough. Sometimes OpenMax HDMI starts up with volume set to zero and you hear nothing.

That sounds like it would have an effect on the HD stuttering, but perhaps not the OSD Lack of display?

I suggest look at the log and see if there are any messages about OpenGL errors.

You should not need more than 256 for GPU memory. Check by running top. You should see "KiB Mem : 766884 total," if you have 256MB set. If you see something in the 900000 range, your setting of GPU memory did not take effect.

The "performance" scaling_governor is set and I have run through all the steps on the wiki page. Happily, we now have stutter-free HD playback .

Unfortunately, there's still no OSD. There are a lot of entries saying "glGetError 0x502" on the console (not in the log) which is apparently the OpenGL error code for "invalid operation". There are also a lot of lines there and in the log that say:

I did install from mythtv-light. I did not knowingly activate "Experimental OpenGL" - where might I check this? Nothing else installed, this was a fresh Raspbian Stretch install and then your packages.

I did not knowingly activate "Experimental OpenGL" - where might I check this?

Set it this way
sudo raspi-config -> 7 Advanced Options -> A7 GL Driver
You should leave it as original driver.
I am not sure how to check if it was changed, but you can just set it back to original and try again.

That OpenGLES mesa is the wrong OpenGLES version. It is a simulated OpenGLES under X11. The OpenGLES library we use is preinstalled in /opt/vc/lib/ When they moved from jessie to stretch they renamed some of the OpenGLES libraries in /opt/vc/lib, which caused MythTV a problem. The build has been changed to accommodate that, and we add links in /usr/share/mythtv/lib that point to the correct libraries to use. You could check those links and make sure they all point to valid libraries. If those links are broken it may cause your problem.

It is possible something changed in recent raspbian that is causing a problem. Check your raspbian version this way
cat /etc/rpi-issue
I am using 2017-08-16. If you have a newer version you could try installing 2017-08-16 version of raspbian. You can download older versions from http://downloads.raspberrypi.org/raspbian/images/
If you find that a newer version of raspbian is causing the failure let me know the issue date so that I can look into it.

G1 and G2 seem to add the vc4-kms-v3d and vc4-fkms-v3d overlays in config.txt. The first of those has this to say in the README: "Running startx or booting to GUI while this overlay is in use will cause interesting lockups."

Something else got messed up; taking those out of config.txt (ie. returning to G3) and GPU memory of 256M has us back to the no OSD displaying and the GL errors from my post above:

I have the same issue. I got a new Raspberry Pi 3 b+ and installed stretch and then mythtv-lite for stretch+myth29, and set the gpu memory to 256M.
I've done nothing else whatsoever.
Running mythfrontend gave:

The frontend became quite unstable, crashing out whenever I fast forwarded or rewound within a recording. I suspect I've messed with too many things and could do with starting again. Did you use the latest version of stretch, stringer26?